"The art of painting original arrangements composed of elements taken from conceived rather than perceived reality."
Apollinaire, The Beginnings of Cubism, 1912.
The first thing one must understand about cubism, before one draws a conclusion about it "generally", is that it is no more a means of obfuscation than it is a means of articulation. When a human being, or any being, perceives something with its eyes, it only captures a two-dimensional glimpse into the entirety of the thing. The mind knows, certainly, that this thing is (let us assume) three-dimensional; thus, the picture the eyes communicate may be said to be incomplete, and even "false". The information provided by the eyes is, taken alone, inaccurate. Enter Pablo Picasso, enter Georges Braque; enter cubism.
Bunkey's (deleted) malarkey about Picasso inventing cubism because he was "afraid of syphilis, and felt it comforting reducing attractive women into shapes and non-contexual impressions" is not only immaterial, it is the perfect example of how to ruin any art of any medium of any era, ever. Picasso is not in his paintings. Picasso is not to be considered in the consideration of the art. Let us not obscure a manifestation of genius by examining it through the filter of trivia or gossip; it only serves to leave us further away from that which we would engage.
Cubism was going to exist with or without Picasso, because it was a natural step in the history of art. It sought to go beyond the photographic image, and beyond perception as perception had been perceived. It wanted to improve the eyes.
Though cubism "developed" into existence, rather than having a simple "date of birth", its tenets have been said to have first manifested in the work of Picasso with his "Les Demoiselles d'Avignon", 1906-7. At least one source reports that cubism first became "well-established" around the year 1910.
I can remember looking at a Picasso of a naked woman laying on a blue sofa. Her back was turned, but the effect of cubistic manipulation made her breasts visible. Now there is no way that I could ever see a woman naked on a couch, without it occurring to me on some level that her breasts were borne, nor is there any way I could see a woman laying on a couch with her back turned without wondering if her eyes are open or closed. This is why cubism exists--to improve the eyes, to capture the thing more accurately than it can be captured without fragmentation. (This is easy to miss, if one becomes preoccupied with the immaterial nonsense one hears about Picasso's fear of syphilis.)
http://www.ibiblio.org/wm/paint/tl/20th/cubism.html
http://www.absolutearts.com/masters/names/Picasso_Pablo.html